DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant’s arguments, see Pages 5-8 of the response, filed 05/08/2026, with respect to the rejection(s) under 35 U.S.C. §103, have been fully considered and are persuasive. As discussed in the interview conducted on 03/30/2026, the previously cited prior art fails to disclose the amendments to Claim 1 of the surface portion at least partially surrounding the airfoil root, the airfoil root extending outwardly from the surface portion. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Nagle (US Patent No: 9,920,629).
Claim Objections
Claim 14 is objected to because of the following informalities: “further comprising a middle portion at least partially surrounds” should read “further comprising a middle portion at least partially surrounding”. Appropriate correction is required.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1, 4-6, 9-10, 12, 15, 18, and 22-23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nolcheff (US Patent 11,181,120) in view of Nagle (US Patent No: 9,920,629), Joudon (WO 2022/208002 A1, with US Publication No: 2024/0175363 being used as an English translation) and Gerakis (US Patent No: 8,100,653).
Regarding Claim 1: Nolcheff discloses a composite airfoil (Figure 3, No. 204; Column 9, Lines 16-19) for a gas turbine engine (100) having a disk (202) and a fan hub (222) covering the disk (Figure 3), wherein an airfoil root (210) attaches the airfoil to the disk (Figure 3); however, Nolcheff fails to disclose the airfoil comprising a spar formed by an airfoil root and an inner portion, the airfoil root having a first solid fiber composite, and the inner portion including a hollow fiber composite, the hollow fiber composite having hollow fibers and solid reinforcing fibers, and a surface portion at least partially surrounding the inner portion and a portion of the airfoil root, the airfoil root extending outwardly from the surface portion, the surface portion including a second solid fiber composite.
Nagle teaches a composite airfoil (Figure 6A, No. 10; Column 2, Lines 58-60) comprising a surface portion (30) at least partially surrounding an inner portion (16) and a portion of an airfoil root (18) (Figure 6A – the surface portion surrounds the portion of the airfoil root 18 from the bottom of the surface portion 30 to the top of root 18 marked by the first dotted line), the airfoil root extending outwardly from the surface portion (Figure 6A – root 18 extends outwardly from the bottom of the surface portion 30).
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to make the airfoil of Nolcheff with a surface portion at least partially surrounding the inner portion and a portion of the airfoil root, the airfoil root extending outwardly from the surface portion, as taught by Nagle, for the purpose of providing the airfoil with desirable structural characteristics and the most efficient, lightest structure (Column 1, Lines 25-32; Column 4, Lines 15-18).
Joudon teaches an airfoil (Figure 2, No. 7) for a gas turbine engine (Figure 1, No. 1), the airfoil comprising a spar (Figure 3, No. 21) formed by an airfoil root (24, 26) and an inner portion (25), the airfoil root having a first solid fiber composite (Paragraph [0071], Lines 1-3), and the inner portion including a hollow fiber composite, the hollow fiber composite having solid reinforcing fibers (Paragraph [0071], Lines 1-3); and a surface portion (22) at least partially surrounding the inner portion (Figure 2), the surface portion including a second solid fiber composite (23) (Paragraph [0067], Lines 1-4).
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to make the airfoil of Nolcheff, as modified by Nagle, with a spar and fiber composites, as taught by Joudon, for the purpose of increasing the tensile stiffness of the structure of airfoil while maintaining a reduced mass (Paragraph [0074], Lines 1- 4).
Gerakis teaches an airfoil (Figure 1) for a gas turbine engine, the airfoil comprising an inner portion (Figure 3A, No. 6) including a hollow fiber composite having hollow fibers (Claim 12).
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to make the inner portion of the airfoil of Nolcheff, as modified by Nagle and Joudon, with hollow fibers, as taught by Gerakis, for the purpose of providing the inner portion with a much higher loadability and optimized tensile strength (Column 3, Lines 24-25; Column 4, Lines 53-55).
Regarding Claim 4: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, wherein the hollow fiber composite includes hollow carbon fibers having a density ranging from 1 gram per cubic centimeter to 1.5 grams per cubic centimeter (property of the material - the prior art airfoil structure is identical to the claimed airfoil structure, and therefore the prior art airfoil has the same properties as the claimed airfoil, including density of the hollow carbon fibers. See MPEP 2112.01).
Regarding Claim 5: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, wherein the hollow fiber composite includes hollow carbon fibers having a tensile modulus ranging from one hundred seventy GPa to two hundred fifty GPa (property of the material - the prior art airfoil structure is identical to the claimed airfoil structure, and therefore the prior art airfoil has the same properties as the claimed airfoil, including tensile modulus of the hollow carbon fibers. See MPEP 2112.01).
Regarding Claim 6: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, wherein the hollow fiber composite includes hollow carbon fibers having a tensile strength ranging from two GPa to five GPa (property of the material - the prior art airfoil structure is identical to the claimed airfoil structure, and therefore the prior art airfoil has the same properties as the claimed airfoil, including tensile strength of the hollow carbon fibers. See MPEP 2112.01).
Regarding Claim 9: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, wherein the inner portion is less dense than the surface portion and the surface portion is less dense than the airfoil root (property of the material – the prior art airfoil structure is identical to the claimed airfoil structure, and therefore the prior art airfoil has the same properties as the claimed airfoil, including density. See MPEP 2112.01).
Regarding Claim 10: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, further comprising a middle portion at least partially surrounding the inner portion and at least partially surrounded by the surface portion; wherein the middle portion is less dense than the inner portion, the inner portion is less dense than the surface portion, and the surface portion is less dense than the airfoil root (property of the material – the prior art airfoil structure is identical to the claimed airfoil structure, and therefore the prior art airfoil has the same properties as the claimed airfoil, including density. See MPEP 2112.01).
Regarding Claim 12: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, further comprising a middle portion (Nagle: 20, 22) at least partially surrounding the inner portion and at least partially surrounded by the surface portion (Nagle: Figure 6A); wherein the middle portion has a lower tensile strength than the inner portion, the inner portion has a lower tensile strength than the surface portion, and the surface portion has a lower tensile strength than the airfoil root (property of the material – the prior art airfoil structure is identical to the claimed airfoil structure, and therefore the prior art airfoil has the same properties as the claimed airfoil, including tensile strength. See MPEP 2112.01).
Regarding Claim 15: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, wherein the hollow fiber composite has less than one weight percent metal by total weight of the hollow fiber composite and the second solid fiber composite has less than one weight percent metal by total weight of the second solid fiber composite (Joudon: spar contains no metal i.e. 0% weight metal).
Regarding Claim 18: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, further comprising a middle portion (Nagle: 20, 22) at least partially surrounding the inner portion and at least partially surrounded by the surface portion (Nagle: Figure 6A), the middle portion including a foam (Nagle: Column 3, Lines 17-19).
Regarding Claim 22: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, wherein the airfoil is rotatable about a pitch axis (Joudon: Figure 2, No. "Y") that is non-parallel to a longitudinal centerline axis ("X") of the gas turbine engine (Figure 2).
Regarding Claim 23: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, wherein the inner portion has a lower tensile strength than the surface portion, and the surface portion has a lower tensile strength than the airfoil root (property of the material – the prior art airfoil structure is identical to the claimed airfoil structure, and therefore the prior art airfoil has the same properties as the claimed airfoil, including tensile strength. See MPEP 2112.01).
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nolcheff, Nagle, Joudon, and Gerakis as applied to Claim 1 above, and further in view of Noland (US Patent No: 5,338,605).
Regarding Claim 7: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1; however, Nolcheff fails to disclose the hollow fiber composite includes hollow carbon fibers having a cross section with one to ten channels.
Noland teaches hollow carbon fibers (Figure 1, No. 10) having a cross section with one channel (14).
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to make the hollow carbon fibers of the airfoil of Nolcheff, as modified by Nagle, Joudon, and Gerakis, with a channel, as taught by Noland, for the purpose of improving the insulation of the carbon fibers (Column 5, Lines 27-29).
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nolcheff, Nagle, Joudon, and Gerakis as applied to Claim 1 above, and further in view of Boszor (US Patent No: 5,509,781).
Regarding Claim 8: Nolcheff, as modified by Nagle, Joudon and Gerakis, discloses the airfoil of Claim 1, wherein the airfoil has a cross section with an airfoil cross section width and an airfoil cross section thickness, and the inner portion has a cross section with an inner portion thickness, the airfoil inner portion thickness and the first airfoil cross section thickness being measured along coinciding lines; however, Nolcheff fails to disclose the inner portion thickness having a length ranging from 0.25 to 0.9 times a length of the airfoil cross section thickness.
Boszor teaches a gas turbine engine composite airfoil (Figures 1-2, No. 12) having a cross section thickness (Figure 5, No. 2Ts + Tc), the airfoil comprising an inner portion (Figure 4, No. 14) also having a thickness (Tc), wherein the inner portion thickness has a length ranging from 0.25 to 0.9 times a length of the airfoil cross section thickness (Column 3, Lines 9-12).
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to make the inner portion thickness of the airfoil of Nolcheff, as modified by Nagle, Joudon, and Gerakis, having a length ranging from 0.25 to 0.9 times a length of the airfoil cross section thickness, as taught by Boszor, for the purpose of making the airfoil lighter and more temperature-resistant in a way that is especially suitable for absorbing compressor blade fragments (Column 1, Lines 44-49).
Claim(s) 13, 14, and 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nolcheff, Nagle, Joudon, and Gerakis as applied to Claim 1 above, and further in view of Velicki (US Patent No: 6,431,837).
Regarding Claim 13: Nolcheff, as modified by Nagle, Joudon and Gerakis, discloses the airfoil of Claim 1, wherein the inner portion including hollow reinforcing fibers; however, Nolcheff fails to disclose the inner portion being a laminated composite having a plurality of plies.
Velicki teaches a gas turbine engine composite airfoil (Figure 1) comprising an inner portion (12), wherein the inner portion is a laminated composite (Column 2, Lines 16-18) having a plurality of plies (Figure 3, No. 12; Column 6, Lines 25-28).
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to make the inner portion of the airfoil of Nolcheff, as modified by Nagle, Joudon, and Gerakis, a laminated composite with a plurality of plies, as taught by Velicki, for the purpose of producing a more airfoil design (Column 3, Lines 52-54).
Regarding Claim 14: Nolcheff, as modified by Nagle, Joudon and Gerakis, discloses the airfoil of Claim 1, further comprising a middle portion (Nagle: 20, 22) at least partially surrounding the inner portion at is at least partially surrounded by the surface portion (Nagle: Figure 6A), wherein the middle portion includes a foam (Nagle: Column 3, Lines 17-19). Nolcheff, however, fails to disclose the inner portion being a laminated composite having a plurality of plies.
Velicki teaches a gas turbine engine composite airfoil (Figure 1) comprising an inner portion (12), wherein the inner portion is a laminated composite (Column 2, Lines 16-18) having a plurality of plies (Figure 3, No. 12; Column 6, Lines 25-28).
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to make the inner portion of the airfoil of Nolcheff, as modified by Nagle, Joudon, and Gerakis, a laminated composite with a plurality of plies, as taught by Velicki, for the purpose of producing a more airfoil design (Column 3, Lines 52-54).
Regarding Claim 16: Nolcheff, as modified by Nagle, Joudon, and Gerakis, discloses the airfoil of Claim 1, wherein the inner portion includes a hollow carbon fiber; however, Nolcheff fails to disclose the hollow fiber composite of the inner portion is a laminated composite with at least one ply.
Velicki teaches a gas turbine engine composite airfoil (Figure 1) comprising an inner portion (12), wherein the inner portion is a laminated composite (Column 2, Lines 16-18) having a plurality of plies (Figure 3, No. 12; Column 6, Lines 25-28).
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to make the inner portion of the airfoil of Nolcheff, as modified by Nagle, Joudon, and Gerakis, a laminated composite with plies, as taught by Velicki, for the purpose of producing a more airfoil design (Column 3, Lines 52-54).
Allowable Subject Matter
Claim 21 is allowed. See previous office action for reasons for allowance.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MICHAEL L SEHN whose telephone number is (571)270-3564. The examiner can normally be reached M-F 8:30 AM-6 PM, every other Friday off.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Courtney Heinle can be reached at 571-270-3508. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/MICHAEL L SEHN/Primary Examiner, Art Unit 3745
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